Product of C-reactive protein and fasting C-peptide indicates cardiovascular risk in type 2 diabetes: A real-world study

BACKGROUND The combined effects of C-reactive protein (CRP) and fasting C-peptide (FCP) on cardiovascular risk remain unclear. AIM To introduce a novel variable, the CRP-FCP product and to evaluate whether it better reflects the cardiovascular risk burden than either biomarker alone in patients with type 2 diabetes mellitus (T2DM). METHODS Overall, 8486 patients with T2DM were enrolled and stratified into quartiles based on CRP-FCP product to compare their clinical characteristics. The associations of CRP, FCP, and the CRP-FCP product with cardiovascular events (CVEs), cerebrovascular events (CBVEs), and cardio-CBVEs (CCBVEs, defined as the presence of CVEs and/or CBVEs) were analyzed by logistic regression. Receiver operating characteristic (ROC) curve analyses were performed to evaluate the discriminative performance of the CRP-FCP product. RESULTS The adjusted prevalences of CVEs, CBVEs, and CCBVEs increased significantly across the CRP-FCP product quartiles (all P < 0.05 for trend). In fully adjusted models, the CRP levels were positively associated with CBVEs (P = 0.016) and CCBVEs (P = 0.005), but not with CVEs (P = 0.070). Conversely, higher FCP levels were associated with an increased risk of CVEs (P = 0.039) and CCBVEs (P = 0.007), but not with CBVEs (P = 0.290). Notably, the CRP-FCP product was independently associated with all three outcomes (all P < 0.05). ROC analyses showed that the area under the curve values of the CRP-FCP product were 0.550 for CVEs, 0.555 for CBVEs, and 0.558 for CCBVEs. CONCLUSION The CRP-FCP product was linked to an increased risk of CVEs, CBVEs and CCBVEs. The CRP-FCP product may provide a more comprehensive assessment of the cardiovascular risk burden than CRP or FCP alone in patients with T2DM.